Dunn is an agent of the U.S. Customs and Border Protection.
History[]
Markham intended to assign Dunn to team up with Brian O'Conner to work undercover and arrest Carter Verone. As Brian saw Dunn drinking a soda with "Gallo's Pizza" written on it, he asked him a trick question, whether a Gallo 12 or a Gallo 24 would be a better motor for his Nissan Skyline. Dunn answered 24, not knowing that there were no such motors; this proved to the others that he wasn't fit for the job, and Brian ended up choosing his own partner.
Later, after Brian and Roman saved Monica and allowed U.S. Customs to arrest Verone. Markham tasked Dunn with collecting the remaining money recovered from Roman.